Studies On The Physiological Effects Of Environmental Factors To Four Major Coconut Cultivars

Some physiological indicators were researched to four major coconut cultivars, such as Hainan Tall, Red Dwarf, Yellow Dwarf and Aromatic Green Dwarf. Chlorophyll fluorescence parameters of the cold treated coconut seedlings was also measured, and the mineral element changes in the leaves of the four coconut cultivars was analyzed, such as N, P, K, Ca, Mg, Fe, Mn, Cu, Zn. Besides, the content of the gross caloric value, the soluble sugar and the total phenolics of the coconut leaves were determined, and then the differences were analyzed, too. The above results were as below.(1) According to the analysis of the Chlorophyll fluorescence parameters, the Aromatic Green Dwarf was highest affected by the low temperature for all four cultivars. At the same time, the Yellow Dwarf was less affected, the red Dwarf and the Hainan Tall were least affected.(2) There were significant differences of the contents of the mineral elements in the different areas and different seasons. During the period of coconut cultivating, some adjustment should be made according to the soil condition and the seasonal changes of the contents.(3) In November, the gross caloric value of the coconut leaves had significant difference compared with that of the other months, and there were also significances in different areas.(4) To all the four cultivars, the soluble sugar in coconut leaves had a significant increase in January. The content of the soluble sugar of the Aromatic Green Dwarf leaves was higher than that of other cultivars and also had obvious seasonal changes.(5) The Hainan Tall had the different seasonal changes of the total phenolics in different areas. The Red Dwarf and the Aromatic Green Dwarf had significant decreases of the total phenolics content in January. In Wenchang, the total phenolics content of the Hainan Tall and the Red Dwarf was significantly lower than those of the Yellow Dwarf and the Aromatic Green Dwarf.